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1. Field of the Invention
The invention is related to the field of communication systems, and in particular, to a system that processes number portability data for a call.
2. Description of the Prior Art
Number portability provides users the ability to retain their phone number when changing either their service provider, location or service. Switching telephone companies is one example of changing service providers. One example of changing services is changing from Plain Old Telephone Service (POTS) to Integrated Services Digital Network (ISDN).
FIG. 1 depicts a system level block diagram of a prior solution for call processing with number portability. In FIG. 1, a call processing system 130 and a call processing system 150 are disclosed in a pending U.S. patent application Ser. No., entitled xe2x80x9cSystem and Method for Processing a Callxe2x80x9d, filed on Nov. 5, 1999, which is hereby incorporated by reference. An interexchange carrier (IXC) 120 typically queries an IXC Service Control Point (SCP) 122 for number portability data. The number portability data could be any data or information associated with providing number portability. However, changes in standards for number portability allow the originating network such as a local telephone company 110 to query a local telephone company SCP 112 for the number portability data.
FIG. 2 depicts a message sequence chart for a prior solution for call processing with number portability. In FIG. 2, the IXC 120 has agreed to accept the number portability data from the local telephone company 110. A local telephone company switch 114 begins processing of a call by querying the SCP 112 with an invoke message for the number portability data. The SCP 112 processes the invoke message and identifies the number portability data for the call. The SCP 112 transmits a response with the number portability data to the switch 114.
The switch 114 transmits an Initial Address Message (IAM) including the number portability data for the call using Signaling System #7 (SS7) to a signaling processor 132. The signaling processor 132 then receives the IAM with the original number portability data. The signaling processor 132 processes the IAM to generate and transmit a first route instruction for a routing system 134 based on the processing of the IAM with the number portability data. The signaling processor 132 also transmits the IAM with the number portability data to the signaling processor 152.
The signaling processor 152 then receives the IAM with the number portability data. The signaling processor 152 processes the IAM. The signaling processor 152 then generates and transmits a second route instruction for a routing system 154 based on the processing of the IAM with the number portability data. The signaling processor 152 also transmits the IAM with the number portability data to a local telephone company switch 164 in a local telephone company 160. The switch 164 processes the IAM. The switch 164 responds with a series of messages for call setup, which are not shown for the sake of clarity. Those skilled in the art understand how the call is set up between the switch 114 and the switch 164 via the routing system 134, the packet network 140, and the routing system 154.
The problem is that the number portability data from the local telephone company 110 may not always be correct. The IXC 120 then misroutes the call with the faulty number portability data. Call misrouting and then call failure may decrease the caller""s satisfaction with the IXC""s 120 telecommunication service. For long distance calls, customers usually call the IXC 120 if there are problems with call routing, which result in call failure. In order to prevent call failure and properly route calls, the IXC 120 needs the ability to obtain correct number portability data.
The invention solves the above problem by identifying incorrect original number portability data from a first network and obtaining new number portability data. The invention advantageously prevents call misrouting due to incorrect number portability data from the first network. A second network avoids decreasing customer satisfaction by properly routing calls with the new number portability data. The second network receives original number portability data from the first network. The second network then determines whether to use the original number portability data from the first network for call routing. If the original number portability data from the first network is not used for call routing, the second network generates and transmits a query to obtain new number portability data for call routing. The second network receives the new number portability data for call routing in response to the query. The second network then generates and transmits a route instruction using the new number portability data. If the original number portability data from the first network is used for call routing, the second network generates and transmits the route instruction using the original number portability data.
In one embodiment of the invention, the second network determines whether calls are misrouted. The second network then processes the number of misrouted calls to determine whether a threshold has been exceeded. The second network then disregards the original number portability data from the first network for call routing based on the determination that the threshold has been exceeded. In different embodiments of the invention, the threshold may be set on a per trunk basis, per trunk group basis, per Point Code basis, per a first network basis, per called party number basis, or per every call basis. Also, in different embodiments of the invention, the threshold may be a total number of misrouted calls or a misrouted call percentage of total calls, attempted calls, or correctly routed calls.
The invention advantageously identifies incorrect original number portability data from a first network and obtains new number portability data to prevent misrouted calls. In some embodiments, the threshold for misrouted calls ensures that incorrect number portability data is not used and the correct number portability data is used for call routing.